Four years ago, the movement and its potent mix of anger and populism persuaded thousands of costumed and sign-waving conservatives to protest the ballooning deficit and President Obama's health care law. It swept a crop of no-compromise lawmakers into Congress and governor's offices and transformed political up-and-comers, including Florida Sen. Marco Rubio, into household names.

But as many tea party stars seek re-election next year and Rubio considers a 2016 presidential run, conservative activists are finding themselves at a crossroads. Many of their standard-bearers have embraced more moderate positions on bedrock issues such as immigration and health care, broadening their appeal in swing states but dampening grass-roots passion.

"They keep sticking their finger in the eyes of the guys who got them elected," said Ralph King, a co-founder of the Cleveland Tea Party Patriots. "A lot of people are feeling betrayed."

The tea party is a loosely knit web of activists, and some are hoping to rekindle the fire with 2014 primary challenges to wayward Republicans. But many more say they plan to sit out high-profile races in some important swing states next year, a move that GOP leaders fear could imperil the re-election prospects of former tea party luminaries, including the governors of Florida and Ohio.

"It changes the playing field for us," said Tom Gaitens, former Florida director of FreedomWorks, a political action committee that has spent millions of dollars to help tea party candidates. "The most powerful thing we have as a movement is our feet and our vote."

In the summer of 2009, tea party supporters stormed congressional town hall meetings, shouting down lawmakers who had voted for the bank bailout and the stimulus package. The movement's voice grew louder after Democrats passed the health care overhaul, and voters took their outrage to the polls in 2010. The tea party wave stunned Democrats and many moderate Republicans, sweeping the GOP into control of the House and changing the balance of power in many statehouses.

But not long after some tea party stars took office, political analysts said, they were forced to adapt to a changing landscape, particularly in states Obama won in 2012, and to the realities of governing.

The tea party also fell out of favor with many people. At its height after the 2010 elections, a CBS News poll found that 31 percent of those surveyed considered themselves tea party supporters. A May survey found just 24 percent identified with the movement.

Facing sagging approval ratings, tea party Republicans, some of whom were elected by slim margins, shifted tactics.

Fla. Gov. Rick Scott, a former health care company executive who won office by attacking the health law and calling for deep cuts to state spending, has embraced the health law and signed one of the largest budgets in state history, complete with pay raises for teachers. Similarly, Gov. John Kasich, R-Ohio, and Rick Snyder, R-Mich., are battling their GOP-dominated legislatures to expand Medicaid, a big part of the health law.

Tea party supporters were most struck by Rubio, the son of Cuban immigrants. His personal story and unlikely rise to power made him perhaps the most prominent figure in the movement.

As a Senate candidate in 2010, he denounced as "amnesty" any plan that would offer a path to citizenship for those who were in the country illegally. Yet in recent months, he has emerged as a leader of a bipartisan Senate group that developed a plan that includes such a provision. The plan has been panned by conservatives but ultimately could bolster Rubio's standing with Hispanics, a growing demographic group that has voted overwhelmingly Democratic in recent years.

One sweltering July day, a half-dozen tea party protesters gathered under a tree in front of Rubio's Miami office, seeking shade as they denounced his support for an immigration overhaul. But the protest soon turned into more of a support group, with the four men and two women grousing to each other about how Rubio had turned into a "back-stabber," a "liar" and a "flip-flopper."

Juan Fiol, a real estate broker who organized the protest, kept looking at his phone, waiting for calls from fellow tea party supporters that never came.

"It was supposed to be a big event," he said as he waved a large "Don't Tread on Me" flag.

The movement's top strategists acknowledge the tea party is quieter today, by design. It has matured, they said, from a protest movement to a political movement. Large-scale rallies have given way to strategic letter-writing and phone-banking campaigns to push or oppose legislative agendas in Washington and state capitals. In Michigan and Ohio, for example, leaders have battled the implementation of the president's health law and the adoption of "Common Core" state school standards.

Local activists say they have focused largely on their own communities since Obama's re-election and the ideological drift of some tea party-backed politicians. Many are running for school boards, county commissions and city councils, focusing on issues such as unfunded pension liabilities and sewer system repairs.

"The positions that people are filling at the local levels are more important for the future of the movement and the future of the country," said Jenny Beth Martin, co-founder of the Tea Party Patriots, a national umbrella organization. "It's creating a farm team for the future."

The Republican establishment, however, is concerned about 2014. Party leaders worry about the GOP's most passionate advocates walking away, particularly those supporters angered by the Senate's immigration bill. In a nod to the tea party, business and conservative groups have launched ad campaigns recasting the bill as a national security measure.

The conservative American Action Network spent $750,000 on pro-reform commercials. One ad aimed at Florida voters called the legislation "the toughest border security plan ever passed by Congress" and urged viewers to thank Rubio for "keeping his promise and fighting to secure the border."

National tea party leaders hope to re-energize followers by focusing on two of the movement's chief targets: the Internal Revenue Service and the health law. They said the Obama administration had handed them a recruiting tool when it delayed the law's implementation and when the IRS singled out tea party groups and other conservative political organizations for special scrutiny.

"The very issues that brought us together in the first place are emerging as more center stage than they were in 2009 and 2010," said Matt Kibbe, president of FreedomWorks. "That animates the political conversation and mobilizes our grass roots going into the 2014 election."

Some Republicans are also moving to repair their relationships with the movement.

Rubio recently spoke to about 50 conservative activists and other lawmakers at a meeting of the Senate's tea party caucus. Organizers said he breezed past immigration, instead devoting much of his speech to repealing the health law.